Illegal sand mining activities are rampant in coastal and inland water around the world and result in increased water turbidity, reduced water transparency, damage to fish spawning sites and adverse effects on the health of aquatic ecosystems. However, many sand dredging vessels hide during the day and work at night, rendering conventional monitoring measures ineffective. In this study, illegal sand dredging activities and the associated aquatic environmental effects were investigated in Lake Hongze (the fourth largest freshwater lake in China) using both conventional daytime satellite data, including MODIS/Aqua and Landsat TM/ETM data as well as VIIRS Day/Night Band (DNB) nighttime light (NTL) data, the following results were obtained. (1) The Landsat data revealed that sand dredging vessels first appeared in February 2012 and their number (monthly average: 658) peaked in 2016, and sand dredging stopped after March 2017. (2) The VIIRS NTL data were satisfactory for monitoring nighttime illegal dredging activities, and they more accurately reflected the temporal and spatial distribution characteristics of dredging vessels due to their high frequency. (3) Observations from the MODIS data acquired since 2002 showed three distinct stages of changes in the suspended particulate matter (SPM) concentrations of Lake Hongze that were consistent with the temporal distributions of sand dredging vessels. (4) The contribution of dredging vessels to the increases in SPM concentration was quantitatively determined, and nighttime sand dredging activities were found to have disturbed the waters more significantly. (5) The effectiveness of government measures implemented at various stages to control illegal sand dredging activities were scientifically evaluated. This study provides technological support for government monitoring and the control of illegal sand dredging activities and can serve as a valuable reference for water bodies similar to Lake Hongze worldwide. The evaluation method developed in this study could potentially be applied at a global scale.

Light pollution impacts both intra- and inter-specific interactions, such as interactions between mates and predator–prey interactions. In mobile organisms attracted to artificial lights, the effect of light pollution on these interactions may be intensified. If organisms are repelled by artificial lights, effects of light pollution on intra- and inter-specific interactions may be diminished as organisms move away. However, organisms repelled by artificial lights would likely lose suitable habitat as light pollution expands. Thus, we investigated how light pollution affects both net attraction or repulsion of organisms and effects on intra- and inter-specific interactions. In manipulative field studies using fireflies, we found that Photuris versicolor and Photinus pyralis fireflies were lured to artificial (LED) light at night and that both species were less likely to engage in courtship dialogues (bioluminescent flashing) in light-polluted field plots. Light pollution also lowered the mating success of P. pyralis. P. versicolor is known to prey upon P. pyralis by mimicking the flash patterns of P. pyralis, but we did not find an effect of light pollution on Photuris–Photinus predator–prey interactions. Our study suggests, that for some nocturnal insects, light-polluted areas may act as demographic traps, i.e., areas where immigration exceeds emigration and inhibition of courtship dialogues and mating reduces reproduction. Examining multiple factors affecting population growth in concert is needed to understand and mitigate impacts of light pollution on wildlife.

Blue Light Hazard is an emerging concern for health of population. Nevertheless, acute exposure to blue rays from artificial light is well taken into account by normative requirements applicable to lamps engineering and risk for general population is low. There is also no evidence for a chronic effect of artificial lighting on retina for general population at radiance below exposure limit values. That said, children in the very first years of life constitute a specific population to consider. On one side, eye anatomy of very young infants is different from elder young people or adults. On the other side, infants can be in close contact with some luminous toys or night lights. This paper presents a first approach for taking into account the specific anatomy of newborn infants’ eyes in blue light hazard evaluation. Results show that differences of crystalline lens transparency, focal length and pupil diameter could induce a significantly higher retinal exposure than for adult.

A significant amount of public attention has recently focused on perceived impacts of converting street lighting from incumbent lamp-based products to LED technology. Much of this attention pertains to the higher content of short wavelength light (commonly referred to as “blue light”) of LEDs and its attendant influences on sky glow (a brightening of the night sky that can interfere with astronomical observation and may be associated with a host of other issues). The complexity of this topic leads to common misunderstandings and misperceptions among the public, and for this reason the U.S. Department of Energy Solid-State Lighting Program embarked on a study of sky glow using a well-established astronomical model to investigate some of the primary factors influencing sky glow. This report details the results of the investigation and attempts to present those results in terms accessible to the general lighting community. The report also strives to put the results into a larger context, and help educate interested readers on various topics relevant to the issues being discussed.